In a typical aircraft design, in-flight entertainment (IFE) systems comprise components designed to deliver multi-media content to passengers. These components include, at a basic level, the servers containing the media content, the passenger display systems, and a networking infrastructure that connects the servers to the display systems.
If all content being sent to the passengers was identical, a very simplistic system and network could be utilized. However, given the fact that modern passengers are provided with not only an opportunity to receive multimedia content from one of several channels, but also on-demand videos, the complexity of the system is greatly increased, and the demands on the network infrastructure are high. Generally, the only practical way to design at least the fundamental networking components of such a system is to use fiber optics or high-capacity wire as the medium via which the high volume of data is sent.
In a typical airplane configuration, the servers and other “head-end” equipment have been grouped together in a centralized common general location and provided in enclosures called IFE center (IFEC) racks or cabin equipment centers (CEC). Communications are routed from this centralized location to various area distribution boxes (ADBs) throughout the airplane. These are then routed to the individual locations at which a multimedia display of the multimedia data is desired.
Each of the servers typically have a set of fiber optic outputs and each of the ADBs has a set of fiber optic inputs. Depending on the size and configuration of the airplane, the number of ADBs can vary considerably, e.g., ranging from five to twelve. Furthermore, the number of servers can vary considerably as well, e.g., ranging from two to ten servers. Although it seems that the interconnection and running fibers between the servers and the ADBs should be a straightforward matter, it is, in fact, somewhat complex, since factors such as redundant coverage and a balancing of client loads across servers must be taken into account.
A further issue is that it is desirable to install the same basic system on airplanes of different sizes and configurations, meaning that a custom-made fiber optic harness connecting the servers and the CEC or IFEC output disconnects must be made that varies from plane to plane and based on customer requirements. With a particular customer configuration, a unique fiber optic schematic is provided and a unique fiber optic bundle is made inside of the rack so that the correct and optimal distribution to the ADB fiber optic feeds can be made; these are laid inside of the aircraft fuselage by the airfraimer, and then they are brought to the equipment cabinet.
This is problematic because one needs a unique fiber optic harness for almost every design (depending on the number of servers the customer wants, and other configuration parameters). Almost every internal rack design is a point design (unique), so there is a lot of nonrecurring engineering associated with each head-end rack design. Also, if a mistake is made or an optimizing redesign is desired, the connections between the servers and the ADBs have to change, and if the harness has already been made and installed, is a very time consuming and costly job just to access it, make the changes, install them, and close up. And during this time, the IFE is unavailable—the rack (which is large) must be removed. Finally, if the customer wants to change the configuration (e.g., change the seat count or seat configuration, or change a level of service, such as going to high-definition MPEG, which takes more bandwidth and requires more servers), again this is a big job.
Many planes are bought by leasing companies, so when a plane goes from a first lessee to a second lessee, the latter may want to completely revamp the configuration/cabin due to different business plans, etc. Therefore, one could go from a high end service, with video screens at every seat, to a low end service, where the client simply wants audio at the seat with an overhead monitor (this could change the server requirement from six to two).